Patent attributes
An overhead crane has first and second runway rails that extend parallel to a generally horizontal runway axis and a bridge that extends along a bridge axis that is generally horizontal and perpendicular to the runway axis and that is movable on the runway rails along the runway axis. The bridge includes a first bridge reinforcement member pre-loaded under tension to provide an upward deflection of the bridge rail. The first bridge reinforcement member may have at least two upwardly extending struts and a common upper end where the at least two struts meet, the at least two struts having lower ends mechanically connected to the bridge rail at positions longitudinally spaced apart with respect to the bridge axis. The lower ends of the at least two struts are longitudinally translatable along the bridge rail to adjust the tension on the first bridge reinforcement member to thereby adjust the extent of upward deflection of the bridge rail. The bridge further includes a pair of second bridge reinforcement members extending between the upper end of the first bridge reinforcement member and mechanically connected to the bridge rail proximate the first and second outer ends, the second bridge reinforcement members loaded in compression. The runway rails may be constructed in a similar manner as the bridge rail.
